merge: Add support for trace writing

This pull request extends the trace API to support writing new traces.

- Unify columns of different tables 
- Support column lookup via index
- Use index lookup in trace loader 
- Add property for describing partition keys
- Simplify TraceFormat SPI interface
- Add support for writing traces

**Breaking API Changes**

- `TraceFormat` SPI interface has been redesigned.

7 files changed, 141 insertions, 325 deletions

diff --git a/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureResourceStateTable.kt b/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureResourceStateTable.kt
deleted file mode 100644
index 84c9b347..00000000
--- a/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureResourceStateTable.kt
+++ /dev/null
@@ -1,127 +0,0 @@
-/*
- * Copyright (c) 2021 AtLarge Research
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package org.opendc.trace.azure
-
-import com.fasterxml.jackson.dataformat.csv.CsvFactory
-import org.opendc.trace.*
-import java.nio.file.Files
-import java.nio.file.Path
-import java.util.stream.Collectors
-import kotlin.io.path.extension
-import kotlin.io.path.nameWithoutExtension
-
-/**
- * The resource state [Table] for the Azure v1 VM traces.
- */
-internal class AzureResourceStateTable(private val factory: CsvFactory, path: Path) : Table {
-    /**
-     * The partitions that belong to the table.
-     */
-    private val partitions = Files.walk(path.resolve("vm_cpu_readings"), 1)
-        .filter { !Files.isDirectory(it) && it.extension == "csv" }
-        .collect(Collectors.toMap({ it.nameWithoutExtension }, { it }))
-        .toSortedMap()
-
-    override val name: String = TABLE_RESOURCE_STATES
-
-    override val isSynthetic: Boolean = false
-
-    override val columns: List<TableColumn<*>> = listOf(
-        RESOURCE_STATE_ID,
-        RESOURCE_STATE_TIMESTAMP,
-        RESOURCE_STATE_CPU_USAGE_PCT
-    )
-
-    override fun newReader(): TableReader {
-        val it = partitions.iterator()
-
-        return object : TableReader {
-            var delegate: TableReader? = nextDelegate()
-
-            override fun nextRow(): Boolean {
-                var delegate = delegate
-
-                while (delegate != null) {
-                    if (delegate.nextRow()) {
-                        break
-                    }
-
-                    delegate.close()
-                    delegate = nextDelegate()
-                    this.delegate = delegate
-                }
-
-                return delegate != null
-            }
-
-            override fun hasColumn(column: TableColumn<*>): Boolean = delegate?.hasColumn(column) ?: false
-
-            override fun <T> get(column: TableColumn<T>): T {
-                val delegate = checkNotNull(delegate) { "Invalid reader state" }
-                return delegate.get(column)
-            }
-
-            override fun getBoolean(column: TableColumn<Boolean>): Boolean {
-                val delegate = checkNotNull(delegate) { "Invalid reader state" }
-                return delegate.getBoolean(column)
-            }
-
-            override fun getInt(column: TableColumn<Int>): Int {
-                val delegate = checkNotNull(delegate) { "Invalid reader state" }
-                return delegate.getInt(column)
-            }
-
-            override fun getLong(column: TableColumn<Long>): Long {
-                val delegate = checkNotNull(delegate) { "Invalid reader state" }
-                return delegate.getLong(column)
-            }
-
-            override fun getDouble(column: TableColumn<Double>): Double {
-                val delegate = checkNotNull(delegate) { "Invalid reader state" }
-                return delegate.getDouble(column)
-            }
-
-            override fun close() {
-                delegate?.close()
-            }
-
-            private fun nextDelegate(): TableReader? {
-                return if (it.hasNext()) {
-                    val (_, path) = it.next()
-                    return AzureResourceStateTableReader(factory.createParser(path.toFile()))
-                } else {
-                    null
-                }
-            }
-
-            override fun toString(): String = "AzureCompositeTableReader"
-        }
-    }
-
-    override fun newReader(partition: String): TableReader {
-        val path = requireNotNull(partitions[partition]) { "Invalid partition $partition" }
-        return AzureResourceStateTableReader(factory.createParser(path.toFile()))
-    }
-
-    override fun toString(): String = "AzureResourceStateTable"
-}
diff --git a/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureResourceStateTableReader.kt b/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureResourceStateTableReader.kt
index c17a17ab..da8181fe 100644
--- a/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureResourceStateTableReader.kt
+++ b/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureResourceStateTableReader.kt
@@ -60,42 +60,37 @@ internal class AzureResourceStateTableReader(private val parser: CsvParser) : Ta
         return true
     }
 
-    override fun hasColumn(column: TableColumn<*>): Boolean {
-        return when (column) {
-            RESOURCE_STATE_ID -> true
-            RESOURCE_STATE_TIMESTAMP -> true
-            RESOURCE_STATE_CPU_USAGE_PCT -> true
-            else -> false
-        }
+    override fun resolve(column: TableColumn<*>): Int = columns[column] ?: -1
+
+    override fun isNull(index: Int): Boolean {
+        require(index in 0..columns.size) { "Invalid column index" }
+        return false
     }
 
-    override fun <T> get(column: TableColumn<T>): T {
-        val res: Any? = when (column) {
-            RESOURCE_STATE_ID -> id
-            RESOURCE_STATE_TIMESTAMP -> timestamp
-            RESOURCE_STATE_CPU_USAGE_PCT -> cpuUsagePct
-            else -> throw IllegalArgumentException("Invalid column")
+    override fun get(index: Int): Any? {
+        return when (index) {
+            COL_ID -> id
+            COL_TIMESTAMP -> timestamp
+            COL_CPU_USAGE_PCT -> cpuUsagePct
+            else -> throw IllegalArgumentException("Invalid column index")
         }
-
-        @Suppress("UNCHECKED_CAST")
-        return res as T
     }
 
-    override fun getBoolean(column: TableColumn<Boolean>): Boolean {
+    override fun getBoolean(index: Int): Boolean {
         throw IllegalArgumentException("Invalid column")
     }
 
-    override fun getInt(column: TableColumn<Int>): Int {
+    override fun getInt(index: Int): Int {
         throw IllegalArgumentException("Invalid column")
     }
 
-    override fun getLong(column: TableColumn<Long>): Long {
+    override fun getLong(index: Int): Long {
         throw IllegalArgumentException("Invalid column")
     }
 
-    override fun getDouble(column: TableColumn<Double>): Double {
-        return when (column) {
-            RESOURCE_STATE_CPU_USAGE_PCT -> cpuUsagePct
+    override fun getDouble(index: Int): Double {
+        return when (index) {
+            COL_CPU_USAGE_PCT -> cpuUsagePct
             else -> throw IllegalArgumentException("Invalid column")
         }
     }
@@ -133,6 +128,15 @@ internal class AzureResourceStateTableReader(private val parser: CsvParser) : Ta
         cpuUsagePct = Double.NaN
     }
 
+    private val COL_ID = 0
+    private val COL_TIMESTAMP = 1
+    private val COL_CPU_USAGE_PCT = 2
+    private val columns = mapOf(
+        RESOURCE_ID to COL_ID,
+        RESOURCE_STATE_TIMESTAMP to COL_TIMESTAMP,
+        RESOURCE_STATE_CPU_USAGE_PCT to COL_CPU_USAGE_PCT
+    )
+
     companion object {
         /**
          * The [CsvSchema] that is used to parse the trace.
diff --git a/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureResourceTable.kt b/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureResourceTable.kt
deleted file mode 100644
index 96ee3158..00000000
--- a/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureResourceTable.kt
+++ /dev/null
@@ -1,54 +0,0 @@
-/*
- * Copyright (c) 2021 AtLarge Research
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package org.opendc.trace.azure
-
-import com.fasterxml.jackson.dataformat.csv.CsvFactory
-import org.opendc.trace.*
-import java.nio.file.Path
-
-/**
- * The resource [Table] for the Azure v1 VM traces.
- */
-internal class AzureResourceTable(private val factory: CsvFactory, private val path: Path) : Table {
-    override val name: String = TABLE_RESOURCES
-
-    override val isSynthetic: Boolean = false
-
-    override val columns: List<TableColumn<*>> = listOf(
-        RESOURCE_ID,
-        RESOURCE_START_TIME,
-        RESOURCE_STOP_TIME,
-        RESOURCE_CPU_COUNT,
-        RESOURCE_MEM_CAPACITY
-    )
-
-    override fun newReader(): TableReader {
-        return AzureResourceTableReader(factory.createParser(path.resolve("vmtable/vmtable.csv").toFile()))
-    }
-
-    override fun newReader(partition: String): TableReader {
-        throw IllegalArgumentException("No partition $partition")
-    }
-
-    override fun toString(): String = "AzureResourceTable"
-}
diff --git a/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureResourceTableReader.kt b/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureResourceTableReader.kt
index 5ea97483..a6352613 100644
--- a/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureResourceTableReader.kt
+++ b/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureResourceTableReader.kt
@@ -62,49 +62,42 @@ internal class AzureResourceTableReader(private val parser: CsvParser) : TableRe
         return true
     }
 
-    override fun hasColumn(column: TableColumn<*>): Boolean {
-        return when (column) {
-            RESOURCE_ID -> true
-            RESOURCE_START_TIME -> true
-            RESOURCE_STOP_TIME -> true
-            RESOURCE_CPU_COUNT -> true
-            RESOURCE_MEM_CAPACITY -> true
-            else -> false
-        }
+    override fun resolve(column: TableColumn<*>): Int = columns[column] ?: -1
+
+    override fun isNull(index: Int): Boolean {
+        require(index in 0..columns.size) { "Invalid column index" }
+        return false
     }
 
-    override fun <T> get(column: TableColumn<T>): T {
-        val res: Any? = when (column) {
-            RESOURCE_ID -> id
-            RESOURCE_START_TIME -> startTime
-            RESOURCE_STOP_TIME -> stopTime
-            RESOURCE_CPU_COUNT -> getInt(RESOURCE_CPU_COUNT)
-            RESOURCE_MEM_CAPACITY -> getDouble(RESOURCE_MEM_CAPACITY)
+    override fun get(index: Int): Any? {
+        return when (index) {
+            COL_ID -> id
+            COL_START_TIME -> startTime
+            COL_STOP_TIME -> stopTime
+            COL_CPU_COUNT -> getInt(index)
+            COL_MEM_CAPACITY -> getDouble(index)
             else -> throw IllegalArgumentException("Invalid column")
         }
-
-        @Suppress("UNCHECKED_CAST")
-        return res as T
     }
 
-    override fun getBoolean(column: TableColumn<Boolean>): Boolean {
+    override fun getBoolean(index: Int): Boolean {
         throw IllegalArgumentException("Invalid column")
     }
 
-    override fun getInt(column: TableColumn<Int>): Int {
-        return when (column) {
-            RESOURCE_CPU_COUNT -> cpuCores
+    override fun getInt(index: Int): Int {
+        return when (index) {
+            COL_CPU_COUNT -> cpuCores
             else -> throw IllegalArgumentException("Invalid column")
         }
     }
 
-    override fun getLong(column: TableColumn<Long>): Long {
+    override fun getLong(index: Int): Long {
         throw IllegalArgumentException("Invalid column")
     }
 
-    override fun getDouble(column: TableColumn<Double>): Double {
-        return when (column) {
-            RESOURCE_MEM_CAPACITY -> memCapacity
+    override fun getDouble(index: Int): Double {
+        return when (index) {
+            COL_MEM_CAPACITY -> memCapacity
             else -> throw IllegalArgumentException("Invalid column")
         }
     }
@@ -138,7 +131,7 @@ internal class AzureResourceTableReader(private val parser: CsvParser) : TableRe
     /**
      * Reset the state.
      */
-    fun reset() {
+    private fun reset() {
         id = null
         startTime = null
         stopTime = null
@@ -146,6 +139,19 @@ internal class AzureResourceTableReader(private val parser: CsvParser) : TableRe
         memCapacity = Double.NaN
     }
 
+    private val COL_ID = 0
+    private val COL_START_TIME = 1
+    private val COL_STOP_TIME = 2
+    private val COL_CPU_COUNT = 3
+    private val COL_MEM_CAPACITY = 4
+    private val columns = mapOf(
+        RESOURCE_ID to COL_ID,
+        RESOURCE_START_TIME to COL_START_TIME,
+        RESOURCE_STOP_TIME to COL_STOP_TIME,
+        RESOURCE_CPU_COUNT to COL_CPU_COUNT,
+        RESOURCE_MEM_CAPACITY to COL_MEM_CAPACITY
+    )
+
     companion object {
         /**
          * The [CsvSchema] that is used to parse the trace.
diff --git a/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureTrace.kt b/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureTrace.kt
deleted file mode 100644
index c7e7dc36..00000000
--- a/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureTrace.kt
+++ /dev/null
@@ -1,46 +0,0 @@
-/*
- * Copyright (c) 2021 AtLarge Research
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package org.opendc.trace.azure
-
-import com.fasterxml.jackson.dataformat.csv.CsvFactory
-import org.opendc.trace.*
-import java.nio.file.Path
-
-/**
- * [Trace] implementation for the Azure v1 VM traces.
- */
-public class AzureTrace internal constructor(private val factory: CsvFactory, private val path: Path) : Trace {
-    override val tables: List<String> = listOf(TABLE_RESOURCES, TABLE_RESOURCE_STATES)
-
-    override fun containsTable(name: String): Boolean = name in tables
-
-    override fun getTable(name: String): Table? {
-        return when (name) {
-            TABLE_RESOURCES -> AzureResourceTable(factory, path)
-            TABLE_RESOURCE_STATES -> AzureResourceStateTable(factory, path)
-            else -> null
-        }
-    }
-
-    override fun toString(): String = "AzureTrace[$path]"
-}
diff --git a/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureTraceFormat.kt b/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureTraceFormat.kt
index 1230d857..253c7057 100644
--- a/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureTraceFormat.kt
+++ b/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureTraceFormat.kt
@@ -24,10 +24,15 @@ package org.opendc.trace.azure
 
 import com.fasterxml.jackson.dataformat.csv.CsvFactory
 import com.fasterxml.jackson.dataformat.csv.CsvParser
+import org.opendc.trace.*
+import org.opendc.trace.spi.TableDetails
 import org.opendc.trace.spi.TraceFormat
-import java.net.URL
-import java.nio.file.Paths
-import kotlin.io.path.exists
+import org.opendc.trace.util.CompositeTableReader
+import java.nio.file.Files
+import java.nio.file.Path
+import java.util.stream.Collectors
+import kotlin.io.path.extension
+import kotlin.io.path.nameWithoutExtension
 
 /**
  * A format implementation for the Azure v1 format.
@@ -45,12 +50,68 @@ public class AzureTraceFormat : TraceFormat {
         .enable(CsvParser.Feature.ALLOW_COMMENTS)
         .enable(CsvParser.Feature.TRIM_SPACES)
 
+    override fun create(path: Path) {
+        throw UnsupportedOperationException("Writing not supported for this format")
+    }
+
+    override fun getTables(path: Path): List<String> = listOf(TABLE_RESOURCES, TABLE_RESOURCE_STATES)
+
+    override fun getDetails(path: Path, table: String): TableDetails {
+        return when (table) {
+            TABLE_RESOURCES -> TableDetails(
+                listOf(
+                    RESOURCE_ID,
+                    RESOURCE_START_TIME,
+                    RESOURCE_STOP_TIME,
+                    RESOURCE_CPU_COUNT,
+                    RESOURCE_MEM_CAPACITY
+                )
+            )
+            TABLE_RESOURCE_STATES -> TableDetails(
+                listOf(
+                    RESOURCE_ID,
+                    RESOURCE_STATE_TIMESTAMP,
+                    RESOURCE_STATE_CPU_USAGE_PCT
+                ),
+                listOf(RESOURCE_STATE_TIMESTAMP)
+            )
+            else -> throw IllegalArgumentException("Table $table not supported")
+        }
+    }
+
+    override fun newReader(path: Path, table: String): TableReader {
+        return when (table) {
+            TABLE_RESOURCES -> AzureResourceTableReader(factory.createParser(path.resolve("vmtable/vmtable.csv").toFile()))
+            TABLE_RESOURCE_STATES -> newResourceStateReader(path)
+            else -> throw IllegalArgumentException("Table $table not supported")
+        }
+    }
+
+    override fun newWriter(path: Path, table: String): TableWriter {
+        throw UnsupportedOperationException("Writing not supported for this format")
+    }
+
     /**
-     * Open the trace file.
+     * Construct a [TableReader] for reading over all VM CPU readings.
      */
-    override fun open(url: URL): AzureTrace {
-        val path = Paths.get(url.toURI())
-        require(path.exists()) { "URL $url does not exist" }
-        return AzureTrace(factory, path)
+    private fun newResourceStateReader(path: Path): TableReader {
+        val partitions = Files.walk(path.resolve("vm_cpu_readings"), 1)
+            .filter { !Files.isDirectory(it) && it.extension == "csv" }
+            .collect(Collectors.toMap({ it.nameWithoutExtension }, { it }))
+            .toSortedMap()
+        val it = partitions.iterator()
+
+        return object : CompositeTableReader() {
+            override fun nextReader(): TableReader? {
+                return if (it.hasNext()) {
+                    val (_, partPath) = it.next()
+                    return AzureResourceStateTableReader(factory.createParser(partPath.toFile()))
+                } else {
+                    null
+                }
+            }
+
+            override fun toString(): String = "AzureCompositeTableReader"
+        }
     }
 }
diff --git a/opendc-trace/opendc-trace-azure/src/test/kotlin/org/opendc/trace/azure/AzureTraceFormatTest.kt b/opendc-trace/opendc-trace-azure/src/test/kotlin/org/opendc/trace/azure/AzureTraceFormatTest.kt
index e5735f0d..b73bb728 100644
--- a/opendc-trace/opendc-trace-azure/src/test/kotlin/org/opendc/trace/azure/AzureTraceFormatTest.kt
+++ b/opendc-trace/opendc-trace-azure/src/test/kotlin/org/opendc/trace/azure/AzureTraceFormatTest.kt
@@ -26,8 +26,7 @@ import org.junit.jupiter.api.Assertions.*
 import org.junit.jupiter.api.Test
 import org.junit.jupiter.api.assertThrows
 import org.opendc.trace.*
-import java.io.File
-import java.net.URL
+import java.nio.file.Paths
 
 /**
  * Test suite for the [AzureTraceFormat] class.
@@ -36,54 +35,29 @@ class AzureTraceFormatTest {
     private val format = AzureTraceFormat()
 
     @Test
-    fun testTraceExists() {
-        val url = File("src/test/resources/trace").toURI().toURL()
-        assertDoesNotThrow {
-            format.open(url)
-        }
-    }
-
-    @Test
-    fun testTraceDoesNotExists() {
-        val url = File("src/test/resources/trace").toURI().toURL()
-        assertThrows<IllegalArgumentException> {
-            format.open(URL(url.toString() + "help"))
-        }
-    }
-
-    @Test
     fun testTables() {
-        val url = File("src/test/resources/trace").toURI().toURL()
-        val trace = format.open(url)
+        val path = Paths.get("src/test/resources/trace")
 
-        assertEquals(listOf(TABLE_RESOURCES, TABLE_RESOURCE_STATES), trace.tables)
+        assertEquals(listOf(TABLE_RESOURCES, TABLE_RESOURCE_STATES), format.getTables(path))
     }
 
     @Test
     fun testTableExists() {
-        val url = File("src/test/resources/trace").toURI().toURL()
-        val table = format.open(url).getTable(TABLE_RESOURCE_STATES)
+        val path = Paths.get("src/test/resources/trace")
 
-        assertNotNull(table)
-        assertDoesNotThrow { table!!.newReader() }
+        assertDoesNotThrow { format.getDetails(path, TABLE_RESOURCE_STATES) }
     }
 
     @Test
     fun testTableDoesNotExist() {
-        val url = File("src/test/resources/trace").toURI().toURL()
-        val trace = format.open(url)
-
-        assertFalse(trace.containsTable("test"))
-        assertNull(trace.getTable("test"))
+        val path = Paths.get("src/test/resources/trace")
+        assertThrows<IllegalArgumentException> { format.getDetails(path, "test") }
     }
 
     @Test
     fun testResources() {
-        val url = File("src/test/resources/trace").toURI().toURL()
-        val trace = format.open(url)
-
-        val reader = trace.getTable(TABLE_RESOURCES)!!.newReader()
-
+        val path = Paths.get("src/test/resources/trace")
+        val reader = format.newReader(path, TABLE_RESOURCES)
         assertAll(
             { assertTrue(reader.nextRow()) },
             { assertEquals("x/XsOfHO4ocsV99i4NluqKDuxctW2MMVmwqOPAlg4wp8mqbBOe3wxBlQo0+Qx+uf", reader.get(RESOURCE_ID)) },
@@ -96,14 +70,12 @@ class AzureTraceFormatTest {
 
     @Test
     fun testSmoke() {
-        val url = File("src/test/resources/trace").toURI().toURL()
-        val trace = format.open(url)
-
-        val reader = trace.getTable(TABLE_RESOURCE_STATES)!!.newReader()
+        val path = Paths.get("src/test/resources/trace")
+        val reader = format.newReader(path, TABLE_RESOURCE_STATES)
 
         assertAll(
             { assertTrue(reader.nextRow()) },
-            { assertEquals("+ZcrOp5/c/fJ6mVgP5qMZlOAGDwyjaaDNM0WoWOt2IDb47gT0UwK9lFwkPQv3C7Q", reader.get(RESOURCE_STATE_ID)) },
+            { assertEquals("+ZcrOp5/c/fJ6mVgP5qMZlOAGDwyjaaDNM0WoWOt2IDb47gT0UwK9lFwkPQv3C7Q", reader.get(RESOURCE_ID)) },
             { assertEquals(0, reader.get(RESOURCE_STATE_TIMESTAMP).epochSecond) },
             { assertEquals(2.86979, reader.getDouble(RESOURCE_STATE_CPU_USAGE_PCT), 0.01) }
         )